The study was carried out to determine the effect of garlic extract on the proximate composition and microbial activity of cold and hot smoked Clupea harangus (Atlantic herring fish). In the study, fresh atlantic herring was thawed, eviscerated, weighed, washed properly and folded. Garlic extract was prepared at 100 ml, 75 ml, 50 ml and control with no garlic extract, each treatments were prepared in duplicates and in three batches. The folded atlantic herring was dipped into the garlic extract at the different concentration, the first batch of treatments was oven dried for 40°C for 6 hours (cold smoked), the second batch was oven dried for 65°C for 12 hours (cold smoked) and the third batch was oven dried for 75°C for 18 hours (hot smoked). After oven drying, it was allowed to cool for 20 minutes, samples for microbial analysis was immediately taken in a foil paper and stored in the fridge for a month while the remaining sample was immediately used for proximate analysis. At all hours of drying period, the moisture content decreases and protein content increases with increasing concentration of garlic extract, the lipid content was highest at 75 ml garlic extract and the ash content was highest at 50 ml garlic extract. Total bacteria count decreases with increasing concentration of garlic, increasing temperature and increasing hour of drying. No fungi growth was recorded at all hours of drying period.